1. Field of the Invention
The present invention relates to a boss, and, in particular, to a coupling boss attachable to a chassis base of a plasma display device for coupling a control circuit, a PCB, etc., to the chassis base during the plasma display device fabrication process.
2. Description of the Related Art
A plasma display device generally includes a panel unit, a circuit unit, and a support mechanism. The support mechanism performs a role supporting a plasma display panel (PDP), and a circuit board, and typically may include a chassis, a reinforcing member, and a various kind of bosses. For example, the plasma display panel is attached by a double-faced adhesive tape on one side surface of the chassis and the boss is coupled to another side surface of the chassis in order to support the circuit unit.
The boss typically has a small cylindrical shape, and is attached to and protrudes from the plane of a chassis base. The boss is typically separately fabricated and then attached to the chassis base by means of a press-inserting process.
FIG. 1 shows a cross-sectional view of a conventional plasma display device. The conventional plasma display device includes a filter 101, a plasma display panel 102, a double-faced adhesive tape 104, a chassis base 106, a circuit board 107, bosses 108, and gaskets 105 for electrically connecting the plasma display panel 102 and the circuit board 107. FIG. 2 shows a cross-sectional view of a conventional plasma display device of FIG. 1.
As shown in the FIG. 2, a head portion 1084, which is an end where the boss 108 is press-inserted into the chassis base 106, has a larger diameter than that of a boss cylinder 1082, which is the outer wall of the boss 108, is provided with a head 1084 formed in a disc shape and located at the lowest portion. A coupling groove 1086 has a smaller diameter than that of the boss cylinder 1082 and is located between the head 1084 and the boss cylinder 1082. A threaded portion 1088 is located at an end opposite head 1084.
When the boss 108 having the head 1084 is press-inserted into the chassis base 106, the material of the chassis base 106 is pushed into the vicinity of the coupling groove 1086, and the head 1084 and the boss cylinder 1082 forming the coupling groove 1086 are engaged with the pushed partial material of the chassis base 106 so that a sufficient attaching strength can be obtained.
However, the boss is typically fabricated by means of a forging method, wherein the processing of the coupling groove and the head of the boss is possible only when the thickness of the chassis is greater than 0.8 mm. The processing of the coupling groove and the head of boss becomes difficult and the pull-out force is considerably reduced when the thickness of the chassis is below 0.8 mm.
Recently, improvements in the support mechanisms have been desired for weight reduction and for simplification of a plasma display device. In this regard gradually reducing the thickness of the chassis has been suggested (e.g., from 2.5 mm to 2.0 mm to 1.5 mm to 1.0 mm to 0.8 mm to 0.6 mm). However, the fabrication cost for fabricating the boss according to the related art has increased due to the degree of difficulty of processing such improvements.
The forging method used in boss fabrication has a comparatively high cost. Also, since the coupling groove formed in the boss according to the related art is fabricated by means of a separate process (post-processing) after fabricating the boss cylinder and the head, the fabrication cost further increases.